Patent Literature 1 mentioned below discloses a technique to solve a problem “to detect and analyze characteristics of an inspection piece and identify a defect having level information” as follows. “An inspection system analyzes the level information with the use of a set of initial values of system parameters to capture an initial portion of an abnormality as a defect. The inspection system displays an outline of the captured defect and also displays a movement curve of the potentially captured defect for a threshold parameter. The inspection system selectively changes the parameters to provide a correction threshold, and analyzes the level information on the abnormality with the use of the correction threshold. The inspection system captures an update portion of the abnormality as a defect based on an analysis immediately before the level information and displays the outline of the captured abnormality together with a recalculated movement curve. A step of selectively changing the threshold and recapturing the defect is repeated as desired and a set of corrected threshold parameters is stored for the purpose of being used for prescription of the inspection system (refer to Abstract).